+/* === S Y N F I G ========================================================= */
+/*! \file uniqueid.h
+** \brief Template Header
+**
+** $Id$
+**
+** \legal
+** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**
+** This package is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public License as
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** General Public License for more details.
+** \endlegal
+*/
+/* ========================================================================= */
+
+/* === S T A R T =========================================================== */
+
+#ifndef __SYNFIG_UNIQUEID_H
+#define __SYNFIG_UNIQUEID_H
+
+/* === H E A D E R S ======================================================= */
+
+/* === M A C R O S ========================================================= */
+
+/* === T Y P E D E F S ===================================================== */
+
+/* === C L A S S E S & S T R U C T S ======================================= */
+
+namespace synfig {
+
+class UniqueIDLessThan;
+
+/*! \class UniqueID
+** \brief \todo
+*/
+class UniqueID
+{
+ friend class UniqueIDLessThan;
+
+ int id_;
+
+ explicit UniqueID(int id_):id_(id_) { }
+
+ static int next_id();
+
+public:
+
+ //! Returns the internal unique identifier for this object.
+ /*! The return value from this isn't really useful for
+ ** much other than debug output. Nonetheless, that is
+ ** one step above useless, so here it is. */
+ const int &get_uid()const { return id_; }
+
+ UniqueID():id_(next_id()) { }
+
+ void make_unique() { id_=next_id(); }
+
+ static const UniqueID nil() { return UniqueID(0); }
+
+ operator bool()const { return static_cast<bool>(id_); }
+
+ void mimic(const UniqueID& x) { id_=x.id_; }
+
+ bool operator==(const UniqueID &rhs)const { return id_==rhs.id_; }
+ bool operator!=(const UniqueID &rhs)const { return id_!=rhs.id_; }
+ bool operator<(const UniqueID &rhs)const { return id_<rhs.id_; }
+}; // END of class UniqueID
+
+/*! \class UniqueIDLessThan
+** \brief A function class used for sorting based on UniqueIDs
+*/
+class UniqueIDLessThan
+{
+public:
+ bool operator()(const UniqueID &lhs, const UniqueID &rhs)const
+ { return lhs.id_<rhs.id_; }
+};
+
+
+}; // END of namespace synfig
+
+/* === E N D =============================================================== */
+
+#endif